Starting-valve for internal-combustion engines.



H.T.BRUNS. STARTING VALVE FOR INTERNAL COMBUSTION ENGINES.

APPLIOATION FILED DEOIZS, 1909. I 1,077,795. Patented Nov. 4, 1913.

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HANS THEODOR BB/TJ'NS, F NUREMBERG, GERMANY.

STARTING-VALVE FOB INTERNAL-COMBUSTION ENGINES.

{To all 107mm 1' X may concern Be it known that I, HANS TH. BRUNS, a

' subject of the King of Prussia, residing at upon the compensating piston and its rear Nuremberg, in the Kingdom of Bavaria and German Empire. have invented new and useful Improvements Relating to Starting- Valves for Internal-Combustion Engines, of which the following is a specification.

For starting internal combustion engines, valves operated by compressed air are ordinarily used, As a rule. the compressed air is cut off while the engine is running. In order that the valves do not open under the high explosion pressure, they are arranged so as to open inwardly. Means, however, must be provided to prevent the valve from remaining permanently open, after the engine had once been started. To this end, a compensating piston is used in combination with aspring, which tends to force the valve on its seat. The valve is actuated by the compensating piston, which when placed under pressure, will open the valve, the rear end of the piston serving as a piston adapted to transmit the pressure of the compressed air to operate the valve. Such an arrangement, however, does not make the operation of the starting Valve certain:

Opposite forces balancing each other act end. Atmospheric pressure acts from the outside upon the valve itself while from the inside-the pressure of the working cylinder acts in addition tothe spring tending to close the valve. As long as the pressure in the cylinder is substantially lower than thatof the compressed air, (2'. e. shortly after the opening of the valve), the compressed air will overcome the combined pressures of the spring and of the cylinder and the valve iskept open. Asvthe' pressure in the cylinder rises and reaches a certain amount, it will in conjunction with of the spring overcome the the compressed air and close the valve again. As the compressed air, however, expands in the cylinder, the compressed air acting on the rear end of the piston will again preponderate in force, the valve re-opens and the same operation is repeatedthe valve chatters. According to my present invention, this chattering is avoided by reason of the fact that the compensating piston and the piston adapted to pressure of Specification of Letters iatent. Application filed December 23, 1909. Serial No. 534,587.

mit the pressure of Patented Nov. 4, 1913.

transmit the pressure of the compressed air to operate the valve are separate, so that the compressed air can act on the pressure transmitting piston on one side only while its other side is under atmospheric pressure. In this way, the pressure transmitting piston and the compensating piston can be made of difl'erent areas, so that when the former is operated, the pressures acting upon the same and upon the compensating piston will no longer balance each other. There is no diiiiculty in making the pressure acting upon the pressure transmitting piston as much greater as desired than that acting upon the compensating piston, so that it will always be greater than the forces of the spring and of the air contained in the cylinder, which forces tend to close the valve.

lVit-h reference to the accompanying -drawing: a is the valve upon which the pressure prevailing for the time being in the combustion cylinder acts from below. Z) is the compensating piston which serves to compensate for the pressure exerted by the compressed air, which is used for starting purposes and enters through the open ing 6 to act upon the annular facec. The compensating piston at the other end carries the separate piston d adapted to transthe compressed air to operate the valve, the inward face of which iston is under atmospheric pressure, to which end, the casing j communicates with the atmosphere through an opening a.

Compressed air is admitted through the passage f into the chamber 9, containing the piston d. The compressed air presses upon the entire face of the piston d, whlch has such an area that the valve a will open with certainty and will be maintained in this open position even though the pressure prevailing in the combustion cyllnder be greater than the pressureof the compressed air entering through f. The valve 1s closed by the spring h contained in cas ng y, as soon as the compressed air is discharged from the chamber g.

I claim:

In internal combustion engines the combination with a valve for admitting compressed air to the engine cylinder for starting purposes, adapted to be sub ected to the pressure of compressed air, and an operating piston for said valve, of a spring bearing against that side of the piston opposite to I In testimony whereof I have signed my the side on which it is subjected to the presname to this speclfication in the presence sure of compressed air, and a separate comof two subscribing witnesses.

pensating piston having a smaller area than HANS THEODOR BRUNS. the said operating piston and placed interlVitnesses: mediate between said operating piston and BERNHARD GRAETZ,

said valve. CARL GARRY. 

